Catalyst composition with mixed selectivity control agent and method

ABSTRACT

The present disclosure provides a Ziegler-Natta catalyst composition comprising a procatalyst, a cocatalyst and a mixed external electron donor comprising a first selectivity control agent, a second selectivity control agent and an activity limiting agent. A polymerization process incorporating the present catalyst composition produces a high-stiffness propylene-based polymer with a melt flow rate greater than about 50 g/10 min. The polymerization process occurs in a single reactor, utilizing standard hydrogen concentration with no visbreaking.

PRIORITY CLAIM

This application is a continuation-in-part of application Ser. No.12/390,785, filed on Feb. 23, 2009, which is now U.S. Pat. No.7,893,003, which is a continuation-in-part application of InternationalPatent Application No. PCT/US2008/073882 filed on Aug. 21, 2008 whichclaims priority to U.S. Provisional Patent Applicatiton No. 60/957,888,filed on Aug. 24, 2007, the entire contents of each application areincorporated by reference herein.

BACKGROUND

The demand for high stiffness propylene-based polymers with high meltflow continues to increase as the need for more sophisticated polymerscontinues to grow. Known are polymer catalyst compositions with amixture of selectivity control agents (SCAs). Mixed SCAs enable theproduction of olefin-hased polymers that possess properties contributedfrom each SCA. However, the use of catalyst compositions with mixed SCAsdoes not change the highly exothermic nature of the olefinpolymerization reaction. The excessive heat generated duringpolymerization poses a significant risk to the polymerization reactoroperability. Excessive heat generation and/or inadequate heat removalcan readily disrupt production and/or shut down the reactor.

Desirable would be a catalyst composition for production of highstiffness/high melt flow propylene-based polymers that reduces, oreliminates, the risk of reactor disruption, or shut-down due toexcessive heat.

SUMMARY

The present disclosure provides a catalyst composition andpolymerization process for the production of a propylene-based polymerwith a high melt flow rate and high stiffness. The catalyst compositionis self-limiting and exhibits strong hydrogen response with theproduction of the high melt flow/high stiffness propylene-based polymerunder standard polymerization conditions.

The present disclosure provides a catalyst composition. The catalystcomposition includes a procataiyst composition, a cocatalyst, and amixed external electron donor (M-EED). The M-EED includes an activitylimiting agent (ALA), a first selectivity control agent (SCA1), a secondselectivity control agent (SCA2). SCA1 and SCA2 are present at a moleratio from 0.1-1.0:1.

In an embodiment, the ALA is selected from an aromatic ester or aderivative thereof, an aliphatic ester or a derivative thereof, adiether, a polyfalkylene glycol) ester, and combinations thereof.

In an embodiment, SCA1 is a dimethoxysilane.

In an embodiment, SCA2 is selected from a diethoxysilane, atriethoxysilane, a tetraethoxysilane, a trimethoxysilane, a diether, adialkoxybenzene, a dimethoxysilane containing two linear aikyi groups, adimethoxysilane containing two alkenyl groups, and combinations thereof.

The present disclosure provides a process, In an embodiment, apolymerization process is provided which includes contacting propyleneand optionally at least one other olefin with a catalyst composition ina polymerization reactor under polymerization conditions. The catalystcomposition includes the procataiyst the cocatalyst and the M-EED. Theprocess further includes forming a propylene-based polymer having a meltflow rate of at least 50 g/10 min.

In an embodiment, the catalyst composition self limits thepolymerization reaction.

The present disclosure provides a composition. In an embodiment, apropylene-based polymer Is provided which includes at least 5 ppm of theactivity limiting agent. The propylene-based polymer has a melt flowrate greater than about. 50 g/10 min as measured in accordance with ASTMD 1238-01 at 230° C., 2.16 kg.

An advantage of the present disclosure is the provision of an improvedcatalyst composition.

An advantage of the present disclosure is the provision of an. improvedpolymerization process.

An advantage of the present disclosure is the provision of an improvedpropylene-based polymer.

An advantage of the present disclosure is the provision of a catalystcomposition that produces a high melt flow/high stiffnesspropylene-based polymer, the catalyst composition self-limiting thepolymerization reaction.

An advantage of the present disclosure is a process for producing a highmelt flow/high stiffness propylene-based polymer with standard amountsof hydrogen, without visbreaking.

An advantage of the present disclosure is the provision of apropylene-based polymer with high melt flow with one or more of thefollowing properties: high final melting point, low oligomer content,low or no toxicity, low or no decomposition products, and/or low or nounpleasant odor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the final melting temperature and the meltflow rate for a propylene-based polymer.

FIG. 2 is a graph showing the oligomer content and the melt flow ratefor a propylene-based polymer.

DETAILED DESCRIPTION

In an embodiment, a catalyst composition is provided. The catalystcomposition includes a procataiyst composition, a cocatalyst, and amixed external electron donor (M-EED). The M-EED includes a firstselectivity control agent (SCA1), a second selectivity control agent(SCA2) and an activity limiting agent (ALA). The M-EED includes aSCA1:SCA2 mole ratio from about 0.1:1 to about 1.0:1.

It is understood that the M-EED may include three or more selectivitycontrol agents (SCA3, SCA4, etc.) and/or two or more ALAs.

The procatalyst composition of the present catalyst composition may be aZiegler-Natta procatalyst composition. Any conventional Ziegler-Nattaprocatalyst. may be used in the present catalyst composition. In anembodiment, the Ziegler-Natta procatalyst composition contains atransition metal compound and a Group 2 metal compound. The transitionmetal compound may be a solid complex derived from a transition metalcompound, for example, titanium-, zirconium-, chromium- orvanadium-hydroearbyloxides, hydrocarbyls, halides, or mixtures thereof.

The transition metal compound has the general formula TrXx where Tr isthe transition metal, X is a halogen or a C₁₋₁₀ hydrocarhoxyl orhydrocarhyl group, and x is the number of such X groups in the compoundin combination with a Group 2 metal compound, Tr may be a Group 4, 5 or6 metal. In an embodiment, Tr is a Group 4 metal, such as titanium. Xmay he chloride, bromide, C₁₋₄ alkoxide or phenoxide, or a mixturethereof. In an embodiment, X is chloride.

Nonlimiting examples of suitable transition metal compounds that may beused to form the Ziegler-Natta procatalyst composition are TiCl₄, ZrCl4,HfCl₄, TiBr₄, TiCl₃, Ti(OC₂H₅)₃Cl, Zr(OC₂H₅)₃Cl, Ti(OC₂H₅)₃Br,Ti(OC₃H₇)₂Cl₂, Ti(OC₆H₅)₂Cl₂, Zr(OC₂H₅)₂Cl₂, and Ti(OC₂H₅)Cl₃. Mixturesof such transition metal compounds may be used as well. No restrictionon the number of transition metal compounds is made as long as at leastone transition metal compound is present. In an embodiment, thetransition metal compound is a titanium compound.

Nonlimiting examples of suitable Group 2 metal compounds includemagnesium halides, dialkoxy magnesiums, alkoxymagnesium halides,magnesium oxyhalides, dialkylmagnesiums, magnesium oxide, magnesiumhydroxide, and carboxylases of magnesium. In an embodiment, the Group 2metal compound is magnesium dichloride.

In an embodiment, the Ziegler-Natta procataiyst composition is a mixtureof titanium moieties supported on or otherwise derived from magnesiumcompounds. Suitable magnesium compounds include anhydrous magnesiumchloride, magnesium chloride adducts, magnesium dialkoxides oraryloxides, or earboxylated magnesium dialkoxides or aryloxides. In anembodiment, the magnesium compound is a magnesium di(C₁₋₄)alkoxide, suchas diethoxymagnesium.

Nonlimiting examples of suitable titanium moieties include titaniumalkoxides, titanium aryloxides, and/or titanium halides. Compounds usedto prepare the Ziegler-Natta procataiyst composition include one or moreraagnesium-di(C₁₋₄)alkoxides, magnesium di halides, magnesiumaikoxyhalicles, or mixtures thereof and one or more titanium tetra(C₁₋₄)alkoxides, titanium tetrahalides, titanium(C₁₋₄)alkoxyhalides, ormixtures thereof.

A precursor composition may be used to prepare the Ziegler-Nattaprocataiyst composition as is commonly known in art. The precursorcomposition may be prepared by the ehlorination of the foregoing mixedmagnesium compounds, titanium compounds, or mixtures thereof, and mayinvolve the use of one or more compounds, referred to as “clippingagents”, that aid in forming or solubilizing specific compositions via asolid/solid metathesis. Nonlimiting examples of suitable clipping agentsinclude trialkylborates, especially triethylborate, phenolic compounds,especially cresol, and silanes.

In an embodiment, the precursor composition is a mixedmagnesium/titanium compound of the formula Mg_(d)Ti(OR_(e))_(f)X_(g)wherein R_(e) is an aliphatic or aromatic hydrocarbon radical having 1to 14 carbon atoms or COR′ wherein R′ is an aliphatic or aromatichydrocarbon radical having 1 to 14 carbon atoms: each OR₃ group is thesame or different; X is independently chlorine, bromine or iodine; d is0.5 to 56, or 2-4; or 3; f is 2-116, or 5-15, and g is 0.5-116, or 1-3,or 2, The precursor may be prepared by controlled precipitation throughremoval of an alcohol from the reaction mixture used in its preparation.In an embodiment, the reaction medium comprises a mixture of an aromaticliquid, especially a chlorinated aromatic compound, such aschlorobenzene, with an aikanol, especially ethauol, and an inorganicchlorinating agent. Suitable inorganic chlorinating agents includechlorine derivatives of silicon, aluminum and titanium, such as titaniumtetrachloride or titanium trichloride, and titanium tetrachloride inparticular. The chlorinating agents lead to partial chlorination whichresults in a precursor containing relatively high level of alkoxycomponent(s). Removal of the aikanol from the solution used in thechlorination, results in precipitation of the solid precursor, having adesirable morphology and surface area. The precursor was separated fromthe reaction media. Moreover, the resulting precursor is particularlyuniform particle sized and resistant to particle crumbling as well asdegradation of the resulting procatalyst, In an embodiment, theprecursor composition is Mg3Ti(OEt)_(s)Cl₂.

The precursor is next converted to a solid procatalyst by furtherreaction (halogenation) with an inorganic halide compound, preferably atitanium halide compound, and incorporation of an internal electrondonor. If not already incorporated into the precursor in sufficientquantity, the internal electron donor may be added separately before,during or after halogenation. This procedure may be repeated one or moretimes, optionally in the presence of additional additives or adjuvants,and the final solid product washed with an aliphatic solvent. Any methodof making, recovering and storing the solid procatalyst is suitable foruse in the present disclosure.

One suitable method for halogenation of the precursor is by reacting theprecursor at an elevated temperature with a tetravaient titanium halide,optionally in the presence of a hydrocarbon or halohydroearbon diluent.The preferred tetravaient titanium halide is titanium tetrachloride. Theoptional hydrocarbon or halohydroearbon solvent employed in theproduction of olefin polymerization procatalyst preferably contains upto 12 carbon atoms inclusive, or up to 9 carbon atoms inclusive.Exemplary hydrocarbons include pentane, octane, benzene, toluene,xylene, alkylbenzenes, and decahydronaphthalene. Exemplary aliphatichalohydroearbons include methylene chloride, methylene bromide,chloroform, carbon tetrachloride, 1,2-dibromoethane,1,1,2-triehloroethane, triehloroeyclohexane, dichlorofluoromethane andtetrachlorooctane. Exemplary aromatic halohydroearbons includeehlorobenzene, bromobenzene, dichloroberrzenes and chlorotoSuenes. Thealiphatic halohydrocarbon may be a compound containing ai least twochloride substiluents such as carbon tetrachloride or1,1,2-trichloroethane. The aromatic halohydrocarbon may be chlorobenzeneor o-chlorotoluene.

The halogenaiion may be repealed one or more times, optionallyaccompanied by washing with an inert liquid such as an aliphatic oraromatic hydrocarbon or halohydrocarbon between halogena lions andfollowing haiogenation. Further optionally one or more extractionsinvolving contacting with an inert liquid diluent, especially analiphatic or aromatic hydrocarbon, or aliphatic or aromatichalohydrocarbon, especially at an elevated temperature greater than 100°C. or greater than 110° C. may be employed to remove labile species,especially TiCl₄.

In an embodiment, the Ziegler-Natta procataiyst composition includes asolid catalyst component obtained by (i) suspending a diaikoxy magnesiumin an aromatic hydrocarbon or halohydrocarbon that is liquid at normaltemperatures, (ii) contacting the diaikoxy magnesium with a titaniumhalide and further (iii) contacting the resulting composition a secondtime with the titanium halide, and contacting the diaikoxy magnesiumwith a diester of an aromatic dlcarboxylie acid at some point during thetreatment with the titanium halide in (ii).

In an embodiment, the Ziegler-Natta procataiyst composition Includes asolid catalyst component obtained by (i) suspending a precursor materialof the formula Mg_(d)Ti(OR_(e))_(f)X_(g) (as described previously) in anaromatic hydrocarbon or halohydrocarbon that is liquid at normaltemperatures, (ii) contacting the precursor with a titanium halide andfurther (iii) contacting the resulting composition a second time withthe titanium halide, and contacting the precursor with a diester of anaromatic dicarboxylic acid at some point during the treatment with thetitanium halide in (ii).

The procataiyst composition includes an internal electron donor. As usedherein, an “internal electron donor” is a compound added or otherwiseformed during formation of the procataiyst composition that donates apair of electrons to one or more metals present in the resultantprocatalyst composition. Not bounded by any particular theory, it isbelieved that the internal electron donor assists in regulating theformation of active sites, thereby enhancing catalyst stereoselectivity.

In an embodiment, the internal electron donor is a hi dentate compound.A “bidentale compound,” as used herein, is a compound containing atleast two oxygen-containing functional groups, the oxygen-containingfunctional groups separated by at least one saturated C₂-C₁₀ hydrocarbonchain which may optionally contain heteroatom(s). The bidentate compoundmay be a phthalate, a diether, a succinate, a phenylene dibenzoate, amaieate, a maionate, a glutarate, a dialkoxybenzene, abis(alkoxyphenyl), a diol ester, a keioester, an alkoxyalkyl ester, a.bis(alkoxyalkyl) fluorene, and any combination thereof.

In an embodiment, the internal electron donor is a phthalate, includingdiisobutyl phthalate and/or di-n-butyl phthalate.

In an embodiment, the internal electron donor is9,9-bis(rnethoxymethyl)-9H-fluorene.

In an embodiment, the internal electron donor is a phenylene dibenzoate.

The Ziegler-Natta procatalyst composition may also include an inertsupport material. The support may be an inert solid which does notadversely alter the catalytic performance of the transition metalcompound. Examples include metal oxides, such as alumina, and metalloidoxides, such as silica.

The present catalyst composition includes a cocatalyst The cocatalystfor use with the foregoing Ziegler-Natta procatalyst composition may bean aluminum containing composition. Nonlimiting examples of suitablealuminum containing compositions include organoaluminum compounds, suchas trialkylalurainum-, dialkylaiuminum hydride-, alkylaluminurndihydride-, dialkylaiuminum halide-, alkylaluminumdihalide-,dialkylaiuminum alkoxide-, and alkylaluminurn dialkoxide- compoundscontaining from 1-10, or 1-6 carbon atoms in each alkyl- or alkoxide-group. In an embodiment, the cocatalyst is a C₁₋₄ trialkylaluminumcompound, such as trieihyialuminum (TEA or TEAl). The molar ratio ofaluminum to titanium is 10-200:1, or 35-50:1. In an embodiment, themolar ratio of aluminum to titanium to 45:1.

The present catalyst composition includes a mixed external electrondonor (M-EED) which includes a first selectivity control agent (SCA1), asecond selectivity control agent (SCA2), and an activity limiting agent(ALA). As used herein, an “external electron donor” (or “EED”) is acompound added independent of procataiyst formation that contains atleast one functional group that is capable of donating a pair ofelectrons to a metal atom. Bounded by no particular theory, it isbelieved that provision of one or more external electron donors in thecatalyst composition affects the following properties of the formantpolymer: level of tacticity (i.e., xylene soluble material), molecularweight (i.e., melt flow), molecular weight distribution (MWD), meltingpoint, and/or oligomer level.

Nonlimiting examples of suitable compounds for the SCA include siliconcompounds, such as alkoxysilanes; ethers and polyethers, such as alkyl-,cycloalkyl-, aryl-, mixed alkyl/aryl-, mixed alkyl/cycloalkyl-, and/ormixed cycloalyl/aryl-ethers and/or polyethers; esters and polyesters,especially alkyl, cycloalkyl- and/or aryl-esters of monocarboxylic ordicarboxylic acids, such as aromatic monocarboxylic- ordicarboxylic-acids; and Group 15 or 16 heteroatom-substitutedderivatives of all of the foregoing; and amine compounds, such ascyclic, aliphatic or aromatic amines, more especially pyrrol or pyridinecompounds; all of the foregoing SCA's containing from 2 to 60 carbonstotal and from 1 to 20 carbons in any alkyl or alkylene group, 3 to 20carbons in any cycloalkyl or cycloalkylene group, and 6 to 20 carbons inany aryl or arylene group.

In an embodiment, SCA1 and/or SCA2 is a silane composition having thegeneral formula (I):SiR_(m)(OR′)_(4-m)  (I)

wherein R independently each occurrence is hydrogen or a hydrocarbyl oran amino group, optionally substituted with one or more substituentscontaining one or more Group 14, 15, 16, or 17 heteroatoms. R containsup to 20 atoms not counting hydrogen and halogen. R′ is a C₁₋₂₀ alkylgroup, and m is 0, 1, or 2, In an embodiment, R is C₆₋₁₂ aryl, alkyl oraralkyl, C₃₋₁₂ cycloallyl, C₃₋₁₂ branched alkyl, or C₃₋₁₂ cyclic aminogroup, R′ is C₁₋₄ alkyl, and m is 1 or 2.

In an embodiment, SCA1 is a dimethoxysilane. The dimethoxysilane mayinclude a dimethoxysilane having at least one secondary alkyl and/or asecondary amino group directly bonded to the silicon atom. Nonlimitingexamples of suitable dimethoxysilanes includedicyclopentyldimethoxysilane, methylcyclohexyldimethoxysilane,diisopropyldimethoxy silane, isopropylisobutyldimethoxysilane,diisobutyldimethoxysilane, t-butylisopropyldimethoxysilane,cyclopentylpyrrolidinodiniethoxysilane, bis(pyrrolidino)dimethoxysilane,bis(perhydroisoquinolino)dimethoxysilane, and any combination of theforegoing.

In an embodiment, SCA1 is a stiffness-promoting composition. A“stiffness-promoting composition,” as used herein, is a compositionthat, but for operation according to the process conditions of thepresent disclosure, increases or otherwise enhances the stiffness of aresulting polymer under the polymerization conditions of interest.Nonlimiting examples of suitable stiffness-promoting include any of thedimethoxysilanes disclosed above.

In an embodiment, SCA1 is dicyclopentyldimethoxysilane.

In an embodiment, the SCA2 is a silicon compound selected from adiethoxysilane, a triethoxysilane, a tetraethoxysilane, atrirnethoxysilane, a dimethoxysilane containing two linear alkyl groups,a dimethoxysilane containing two alkenyl groups, a diether, adialkoxybenzene, and any combination thereof.

Nonlimiting examples of suitable silicon compounds for SCA2 includedimethyldirnethoxysiiane, vinylmethyldimethoxysilane,n-octylmethyldimethoxysilane, n-octadecylmethyldimethoxysilane,methyldimethoxysilane, 3-chloropropylmethyldimethoxysilane,2-chloroethylmethyldimethoxysilane, allyldimethoxysilane,(3,3,3-trifluoropropyl)methyldimethoxysilane,n-propylmethyldimethoxysilane, chloromethylmethyldimethoxysilane,di-n-octyldimethoxysilane, vinyl(chloromethyl)dimethoxysilane,methylcyclohexyldiethoxysilane, vinylmethyldiethoxysilane,1-(triethoxysilyl)-2-(diethoxymethylsilyl)ehtane,n-octylmethyldiethoxysilane, octaethoxy-1,3,5-trisilapentane,n-octadecylmethyldiethoxysilane, methacryloxypropylmethyldiethoxysilane,2-hydroxy-4-(3-methyldiethoxysilylpropoxy)diphenylketone,(3-glycidoxypropyl)methyldiethoxysilane, dodecylmethyldiethoxysilane,dimethyldiethoxysilane, diethyldiethoxysilane,1,1-diethoxy-1-silacyclopent-3-ene, chloromethylmethyldiethoxysilane,bis(methyldiethoxysilylpropyl)amine, 3-aminopropylmethyldiethoxysilane,(methacryloxymethyl)methyldiethoxysilane,1,2-bix(methyldiethoxysilyl)ethane, and diisobutyldiethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, benzyltriethoxysilane,butenyltriethoxysilane, (triethoxysilyl)cyclohexane,O-(vinyloxybutyl)-N-triethoxysilylpropylcarbamate,10-undecenyltrimethoxysilane, n-(3-trimethoxysilylpropyl)pyrrole,N-[5-(trimethoxysilyl)-2-aza-1-oxopentyl]caprolactam,(3,3,3-trifuoropropyl)trimethoxysilane, triethoxysilylundecanal ethyleneglycol acetal, (S)-N-triethoxysilylpropyl-O-menthocarbamate,triethoxysilylpropylethylcarbamate,N-(3-triethoxysilylpropyl)4,5-dihydroimidazole,(3-triethoxysilylpropyl-t-butylcarbamate, styrylethyltrimethoxysilane,2-(4-pyridylethyl)triethoxysilane, n-propyltrimethoxysilane,n-propyltriethoxysilane,(S)-N-1-phenylethyl-N′-triethoxysilylpropylurea,(R)-N-1-phenylethyl-N′-triethoxysilylpropylurea,N-phenylaminopropyltrimethoxysilane, N-phenylaminomethyltriethoxysilane,phenethyltrimethoxysilane, pentyltriethoxysilane,n-octyltrimethoxysilane, n-octyltriethoxysilane,7-octenyltrimethoxysilane, S-octanoyl)mercaptopropyltriethoxysilane,n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane,methyltrimethoxysilane, methyltriethoxysilane,N-methylaminopropyltrimethoxysilane, 3-methoxypropyltrimethoxysilane,methacryloxymethyltrimethoxysialne, methacryloxymethyltriethoxysilane,and O-(methacryloxyethyl)-N-(triethoxysilylpropyl)carbamate,tetramethoxysilane and/or tetraethoxysilane.

In an embodiment, SCA2 may be methyicyclohexyldiethoxysilane,di-isobutyldiethoxysilane, n-propyltriethoxysilane, tetraethoxysilane,di-n-butyl-dimethoxysilane, benzyltriethoxysilane,but-3-enyltriethoxysilane, 1 -(triethoxysilyl)-2-pentene,(triethoxysilyl)cyclohexane, and any combination of the foregoing.

In an embodiment, the SCA2 is selected from a dimethoxysilane containingtwo linear alkyl groups, a dimethoxysilane containing two alkenyl groupsor hydrogen, wherein one or more hydrogen atoms may be substituted by ahalogen, and any combination thereof.

In an embodiment, SCA2 may be a diether, a dimer of a diether, adialkoxybenzene, a dimmer of a diatkoxybenzene, a dialkoxybenzene linkedby a linear hydrocarbon group, and any combination thereof. It is notedthat the diethers for the ALA set forth below apply equally asnonlimiting examples for the SCA2 diether.

In an embodiment, SCA2 is a melt flow-promoting composition. A “meltflow-promoting composition,” as used herein, is a composition that, butfor operation according to the process conditions of the presentdisclosure, increases the melt flow rate of a resulting polymer underthe polymerization conditions of interest. The melt-flow promotingcomposition may be any silane composition suitable as SCA2 as disclosedabove, a diether, an alkoxybenzene, an ester, a ketone, an amide, and/oran amine.

In an embodiment, the catalyst composition includes a mole ratio of SCA1to SCA2 that is less than or equal to 1, or 0.1-1.0:1. In a furtherembodiment, the SCA1:SCA2mole ratio is 0.1-0.9:1, or 0.2-0.5:1. Notbounded by any particular theory, it has been found that maintaining theSCA1:SCA2 mole ratio to less than or equal to 1.0, advantageouslyenables both SCAs to contribute to the properties of the formantpropylene-based polymer.

The M-EED includes an activity limiting agent (ALA). An “activitylimiting agent,” as used herein is a material that reduces catalystactivity at elevated temperature, namely, in a polymerization reactor atpolymerization conditions at a temperature greater than about 100° C.Provision of the ALA results in a self-limiting catalyst composition. Asused herein, a “self-limiting” catalyst composition is a catalystcomposition that demonstrates decreased activity at a temperaturegreater than about 100° C. In other words, “self-limiting” is thedecline of catalyst activity when the reaction temperature rises above100° C. compared to the catalyst activity under normal polymerizationconditions with reaction temperature usually below 80° C. In addition,as a practical standard, if a polymerization process, such as ailuidized bed, gas-phase polymerization running at normal processingconditions is capable of interruption and resulting collapse of the bedwith reduced risk with respect to agglomeration of polymer particles,the catalyst composition is said to be “self-limiting.”

As a standardized measure of polymerization activity at elevatedtemperatures for use herein, catalyst activities are adjusted tocompensate for different monomer concentrations due to temperature. Forexample, if liquid phase (slurry or solution) polymerization conditionsare used, a correction factor to account for reduced propylenesolubility in the reaction mixture at elevated temperatures is included,That is, the catalyst activity is “normalized” to compensate for thedecreased solubility compared to the lower temperature, especially a 67°C. standard. The “normalized” activity, at temperature T, or A_(T), isdefined as the measured activity or (weight polymer/weight catalyst/hr)at temperature T, multiplied by a concentration correction factor,[P(67)]/[P(T)], where [P(67)] is the propylene concentration at 67° C.and [P(T)] is the propylene concentration at temperature T. The equationfor normalized activity is provided below.

${{Normalized}\mspace{14mu}{Activity}\mspace{14mu}(A)} = {\frac{\left\lbrack {P(67)} \right\rbrack}{\left\lbrack {P(T)} \right\rbrack} \times {{Activity}(T)}}$

In the equation, the activity at temperature T is multiplied by a ratioof the propylene concentration at 67° C. to the propylene concentrationat temperature T. The resulting normalized activity (A), adjusted forthe decrease in propylene concentration with temperature increase, maybe used for comparison of catalyst activities under varying temperatureconditions. The correction factors are listed below for the conditionsused in the liquid phase polymerization.

67° C. 85° C. 100° C. 115° C. 130° C. 145° C. 1.00 1.42 1.93 2.39 2.983.70

The correction factor assumes that polymerization activity increaseslinearly with propylene concentration under the conditions employed. Thecorrection factor is a function of the solvent or diluent used. Forexample, the correction factors listed above are for a common C₆₋₁₀aliphatic hydrocarbon mixture (Isopar™E, available from Exxon ChemicalCompany), Under gas phase polymerization conditions, monomer solubilityis normally not a factor and activity is generally uncorrected fortemperature difference. That is, activity and normalized activity arethe same.

The “normalized activity ratio” is defined as A_(T)/A₆₇, where A_(T) isthe activity at temperature T and A₆₇ is the activity at 67° C. Thisvalue can be used as an indicator of activity change as a function oftemperature. For example, an A₁₀₀/A₆₇ equal to 0.30 shows that thecatalyst activity at 100° C. is only 30 percent of the catalyst activityat 67° C. It has been found that at 100° C., an A₁₀₀/A₆₇ ratio of 35% orless yields a catalyst system that is a self-limiting system.

The ALA may be an aromatic ester or a derivative thereof, an aliphaticester or derivative thereof, a diether, a poly(alkylene glycol) ester,and combinations thereof. Nonlimiting examples of suitable aromaticesters include C₁₋₁₀ alkyl or cycloalkyl esters of aromaticmonocarboxylic acids. Suitable substituted derivatives thereof includecompounds substituted both on the aromatic ring(s) or the ester groupwith one or more substituents containing one or more Group 14, 15 or 16heteroatoms, especially oxygen. Examples of such substituents include(poly)alkylether, cycloalkylether, arylether, aralkylether,alkylthioether, arylthioether, dialkylamine, diarylamine,diaralkylamine, and trialkylsilane groups. The aromatic carboxylic acidester may be a C₁₋₂₀ hydrocarbyl ester of benzoic acid wherein thehydrocarbyl group is unsubstituted or substituted with one or more Group14, 15or 16 heteroatom containing substituents and C₁₋₂₀(poly)hydrocarbyl ether derivatives thereof, or C₁₋₄ alkyl benzoates andC₁₋₄ ring alkylated derivatives thereof, or methyl benzoate, ethylbenzoate, propyl benzoate, methyl p-methoxybenzcate, methylp-ethoxybenzoate, ethyl p-methoxybenzoate, and ethyl p-ethoxybenzoate.In an embodiment, the aromatic earboxylic acid ester is ethylp-ethoxybenzoate.

In an embodiment, the ALA is an aliphatic ester. The aliphatic ester maybe a C₄-C₃₀ aliphatic acid ester, may be a mono- or a poly- (two ormore) ester, may be straight chain or branched, may be saturated orunsaturated, and any combination thereof. The C₄-C₃₀aliphatic acid estermay also be substituted with one or more Group 14, 15 or 16 heteroatomcontaining substituents. Nonlimiting examples of suitable C₄-C₃₀aliphatic acid esters include C₁₋₂₀ alkyl esters of aliphatic C₄₋₃₀monocarboxylic acids, C₁₋₂₀ alkyl esters of aliphatic C₈₋₂₀monocarboxylic acids, C₁₋₄ allyl mono- and diesters of aliphatic C₄₋₂₀monocarboxylic acids and dicarboxylic acids, C₁₋₄ alkyl esters ofaliphatic C₈₋₂₀ monocarboxylic acids and dicarboxylic acids, and C₄₋₂₀mono- or polycarboxylate derivatives of C₂₋₁₀₀ (poly)glycols or C₂₋₁₀₀(poly)glycol ethers. In a further embodiment, the C₄-C₃₀ aliphatic acidester may be isopropyl myristate and/or di-n-butyl sebaeate.

In an embodiment, the ALA is isopropyl myristate.

In an embodiment, the ALA is a diether. The diether may be a dialkyldiether represented by the following formula.

wherein R¹ to R⁴ are independently of one another an alkyl, aryi oraralkyl group having up to 20 carbon atoms, which may optionally containa group 14, 15, 16, or 17heteroatom, provided that R! and R.2 may be ahydrogen atom. Nonlimiting examples of suitable dialkyl ether compoundsinclude dimethyl ether, diethyl ether, dibutyl ether, methyl ethylether, methyl butyl ether, methyl cyclohexyl ether,2,2-dimethyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane,2,2-di-n-butyl-1,3-dimethoxypropane,2,2-diisobutyl-1,3-dimethoxypropane,2-ethyl-2-n-butyl-1,3-diraethoxypropane,2-n-propyl-2-cyclopentyl-1,3-dimethoxypropane,2,2-dimethyl-1,3-diethoxypropane, 2 -isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane,2-n-propyl-2-cyclohexyl-1,3-diethoxypropane, and9,9-bis(methoxymethyl)fluorene. In a further embodiment, the dialkylether compound is 2,2-diisobutyl-1,3-dimethoxypropane.

In an embodiment, the ALA is a polyfalkylene glycol) ester, Nonlimitingexamples of suitable polyfalkylene glycol) esters include polyfalkyleneglycol) mono- or diaceiates, poly(alkylene glycol) mono- ordi-myristates, poly(alkylene glycol) mono- or di-laurates, poly(alkyleneglycol) mono- or di- oleates, glyceryl tri(acetate), glyceryl tri-esterof C₂₋₁₀ aliphatic earboxyiic acids, and any combination thereof. In anembodiment, the polyfalkylene glycol) moiety of the polyfalkyleneglycol) ester is a poly(ethylene glycol).

In an embodiment, the molar ratio of aluminum to ALA may be 1.4-85:1, or2.0-50:1, or 4-30:1. For ALA that contains more than one carboxylategroup, all the carboxylate groups are considered effective components.For example, a sebacate molecule contains two carboxylate functionalgroups is considered to have two effective functional molecules.

In an embodiment, the catalyst composition includes a mole ratio of Alto M-EED of 0.5-25:1, or 1.0-20:1, or 1.5-15:1, or less than about 6, orless than about 5, or less than 4,5.

In an embodiment, the Al:M-EED mole ratio is 0.5-4.0:1. Not wishing tobe bound by any particular theory, it is believed that the Al/M-EED moleratio of 0.5:1 to 4.0:1provides a sufficient amount of aluminum tosupport the polymerization reaction at normal polymerizationtemperatures. However, at elevated temperature (due to a temperatureexcursion or a process upset, for example), more aluminum species reactwith other catalyst components. This leads to an aluminum deficiencywhich slows the polymerization reaction. The aluminum deficiency causesa corresponding reduction in the number of electron donors complexedwith the aluminum. The free electron pairs of the non-compiexed donorspoison the catalyst system, which self limits the reaction.

As used herein, “total-SCA” is the combined amount (in moles) of SCA1and SCA2. in other words, total-SCA=SCA1 (mole)+SCA2 (mole). The amountof ALA in M-EED enhances catalyst self-limiting capability at elevatedtemperature, while the amount of SCA1 provides stiffness and the amountof SCA2 provides melt flow in the resultant polymer. The total-SCA toALA mole ratio is 0.43-2.33:1, 0.54-1.85:1, or 0.67-1.5:1. The SCA1 tototal-SCA mole ratio is 0.2-0.5:1, 0.25-0.45:1, or 0.30-0.40:1.Applicants have surprisingly and unexpectedly discovered that acontrolled mole ratio of: (1) SCA1 to SCA2, and/or (2) total-SCA to ALA,and/or (3) SCA1 to total-SCA yields a resultant polymer with the uniqueproperties of high melt flow and high stiffness in conjunction with theoperability property of a self-limiting catalyst.

In an embodiment, the mole ratio of total-SCA to ALA is 0.43-2.33:1 andthe mole ratio of SCA1 to total-SCA is 0.2-0.5:1.

In an embodiment, the catalyst composition includes a mole ratio of Alto total-SCA of 1.4-85:1, or 2.0-50:1, or 4.0-30:1.

In an embodiment, the catalyst composition includes a mole ratio oftotal-SCA to ALA that is less than 1,0. Surprisingly and unexpectedly,it has been found that maintaining the mole ratio of total-SCA to ALA toless than 1.0 significantly improves reactor operability.

In an embodiment, the M-EED comprises dicydopentyjdimethoxysilane(SCA1), a melt-flow promoting composition (SCA2), and isopropylmyristate (ALA). In a norther embodiment, SCA2 is selected frommethylcyclohexyldiethoxysilane, diisobutyldiethoxysiiane,di-n-butyl-dirnethoxysilane, n-propyltriethoxysilane,benzyltriethoxysilane, but-3-enyltriethoxysilane, 1-(triethoxysilyi)-2-pentene, (triethoxysilyl)cyclohexane,tetraethoxysilane, 1 -ethoxy-2-(6-(2-edioxyphenoxy)hexyloxy)benzene,1-ethoxy-2-n-pentoxybenzene, and any combination thereof.

The mole ratios between various components of the present catalystcomposition are set forth below in Table 1.

TABLE 1 Mole Ratio Range Al to Ti 10-200:1  Al to M-EED 0.5-25:1 M-EEDto Ti  1-100:1 Al to total-SCA 1.4-85:1 Al to ALA 1.4-85:1 total-SCA toALA 0.43-2.33:1   SCA1 to SCA2 0.1-1.0:1  SCA1 to total-SCA 0.2-0.5:1 

The present catalyst composition may comprise two or more embodimentsdisclosed herein.

In an embodiment, a polymerization process is provided. Thepolymerization process includes contacting propylene and optionally atleast, one other olefin with a catalyst composition in a polymerizationreactor under polymerization conditions. The catalyst composition may beany catalyst composition disclosed herein and includes a procataiyst, acocatalyst and a mixed external electron donor (M-EED) comprising afirst selectivity control agent (SCA1), a second selectivity controlagent (SCA2), and an activity limiting agent (ALA). The process alsoincludes forming a propylene-based polymer having a melt flow rate (MLR)of at least 50 g/10 min as measured in accordance with ASTM D 1238-01test method at 230° C. with a 2.16 kg weight.

In an embodiment, the process includes forming a propylene-based polymerwith a MFR greater than 60 g/10 min, or greater than 70 g/10 min, orgreater than 80 g/1 0 min, or greater than 100 g/10 nun, or greater than50 g/ 10 rain to about 1000 g/10 min.

The process includes contacting propylene and optionally at least oneother olefin with the catalyst composition in a polymerization reactor.One or more olefin monomers can be introduced into the polymerizationreactor along with the propylene to react with the catalyst and to forma polymer, a copolymer, (or a fluidized bed of polymer particles).Nonlimiting examples of suitable olefin monomers include ethylene, C₄₋₂₀α-olefins, such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1 -pentene,1-heptene, 1-octene, 1-decene, 1-dodecene and the like; C4-20 diolefins,such as 1,3-butadiene, 1,3-pentadiene, norbornadiene,5-ethylidene-2-norbornene (ENB) and dieyelopentadiene; C₈₋₄₀ vinylaromatic compounds including styrene, o-, m-, and p-methylstyrene,divinylbenzene, vinylbiphenyl, vinylnapthalene; and halogen-substitutedC₈₋₄₀ vinyl aromatic compounds such as chlorostyrene and fluorostyrene.

In an embodiment, the process includes contacting propylene with thecatalyst composition to form a propylene homopolymer.

As used herein, “polymerization conditions” are temperature and pressureparameters within a polymerization reactor suitable for promotingpolymerization between the catalyst composition and an olefin to formthe desired polymer. The polymerization process may be a gas phase, aslurry, or a bulk polymerization process, operating in one, or more thanone, polymerization reactor. Accordingly, the polymerization reactor maybe a gas phase polymerization reactor, a liquid-phase polymerizationreactor, or a combination thereof.

It is understood that provision of hydrogen in the polymerizationreactor is a component of the polymerization conditions. Duringpolymerization, hydrogen is a chain transfer agent and affects themolecular weight (and correspondingly the melt flow rate) of theresultant polymer.

In an embodiment, polymerization occurs by way of liquid phasepolymerization.

In an embodiment, polymerization occurs by way of gas phasepolymerization. As used herein, “gas phase polymerization” is thepassage of an ascending fluidizing medium, the fluidizing mediumcontaining one or more monomers, in the presence of a catalyst through afluidized bed of polymer particles maintained in a fluidized state bythe fluidizing medium. “Fluidization,” “fluidized,” or “fluidizing” is agas-solid contacting process in which a bed of finely divided polymerparticles is lifted and agitated by a rising stream of gas. Fluidizationoccurs in a bed of particulates when an upward flow of fluid through theinterstices of the bed of particles attains a pressure differential andfrictional resistance increment exceeding particulate weight. Thus, a“fluidized bed” is a plurality of polymer particles suspended in afluidized state by a stream of a fluidizing medium, A “fluidizingmedium” is one or more olefin gases, optionally a carrier gas (such asH₂ or N₂) and optionally a liquid (such as a hydrocarbon) which ascendsthrough the gas-phase reactor.

A typical gas-phase polymerization reactor (or gas phase reactor)includes a vessel (i.e., the reactor), the fluidized bed, a distributionplate, inlet and outlet piping, a compressor, a cycle gas cooler or heatexchanger, and a product discharge system. The vessel includes areaction zone and a velocity reduction zone, each of which is locatedabove the distribution plate. The bed is located in the reaction zone.In an embodiment, the fluidizing medium includes propylene gas and atleast one other gas such as an olefin and/or a carrier gas such ashydrogen or nitrogen.

In an embodiment, the contacting occurs by way of feeding the catalystcomposition into the polymerization reactor and introducing the olefininto the polymerization reactor, In an embodiment, the process includescontacting the olefin with a cocatalyst. The cocatalyst can be mixedwith the procataiyst composition (pre-mix) prior to the introduction ofthe procataiyst composition into the polymerization reactor. In anotherembodiment, cocatalyst is added to the polymerization reactorindependently of the procataiyst composition. The independentintroduction of the cocatalyst into the polymerization reactor can occursimultaneously, or substantially simultaneously, with the procataiystcomposition feed.

In an embodiment, the process includes mixing or otherwise combining theM-EED with the procataiyst composition. The M-EED can be complexed withthe cocatalyst and/or mixed with the procataiyst composition (pre-mix)prior to contact between the catalyst composition and the propylene. Inanother embodiment, the M-EED (or individual components thereof) may beadded independently to the polymerization reactor.

In an embodiment, the process includes maintaining a SCA1:SCA2 moleratio of 0.1-1.0:1.

In an embodiment, the process is a gas phase polymerization process andincludes maintaining a hydrogen-to-propylene (“H₂/C₃”) mole ratio lessthan 0.30 (i.e., 0.30:1). or less than 0.20, or less than 0.18, or lessthan 0.16, or less than 0.08 in a gas phase reactor. Although high meltflow can be achieved by using a high level of hydrogen, it has beenfound that propylene-based polymers produced by way of a H₂/C₃ moleratio greater than 0.30 significantly accelerate an unwanted reaction ofhydrogenation of propylene in the presence of oxidized carbon steel of areactor and reduce catalyst activity. On the other hand, the resultantpropylene-based polymer formed by way of the present process avoidsexcessive amounts of catalytic residue as the H₂/C₃ mole ratio is lessthan 0.3. In a further embodiment, the process is a gas phasepolymerization process as disclosed in copending application Ser. No.29/060250, filed on Feb. 23, 2009, the entire content of which isincorporated by reference herein.

In an embodiment, the gas phase polymerization process includesmaintaining a hydrogen partial pressure below about 80 psi, or belowabout 71 psi, or below about 63 psi.

In an embodiment, the process includes self-limiting the polymerizationprocess when the temperature in the reactor is greater than about 100°C.

In an embodiment the process includes forming the propylene-basedpolymer in a single polymerization reactor.

In an embodiment, the process includes forming a propylene-based polymercontaining at least about 5 ppm ALA and a MFR greater than about 50 g/10min. The ALA is present in an amount of at least about 5 ppm, or atleast about 10 ppm, or at least about 20 ppm, or at least about 30 ppm,or at least about 5 ppm to about 150 ppm. In a further embodiment, theALA is isopropyl myristate (IPM).

In an embodiment, the process includes forming a propylene-based polymercontaining less than about 200 ppm silicon. In a further embodiment, theprocess includes forming a propylene-based polymer containing less than200 ppm, or from about 1 ppm to about 200 ppm, or from about 2 ppm toabout 100 ppm dicylcopentyldirnethoxysilane.

Applicants have surprisingly and unexpectedly discovered that diepresence of the mixed external electron donor provides a catalystcomposition that is self-limiting and produces propylene-based polymerswith high stiffness and high melt flow in a single polymerizationreactor under standard polymerization conditions. Not wishing to bebound by any particular theory, it is believed that the ALA improvesoperability in the polymerization reactor by preventing a run-awayreaction, polymer sheeting, and/or polymer agglomeration caused byexcessive heat. Provision of SCA1 and SCA2 enables the formation of ahigh stiffness (i.e., T_(MF) greater than about 170° C.)/high melt flow(i.e., greater than 50, or 60, or 70, or 100 g/10 min) propylene-basedpolymer with utilization of standard hydrogen levels.

In particular, the present process advantageously produces apropylene-based polymer with high stiffness and high melt flow withoutvisbreaking—a conventional technique for increasing the MFR beyond thehydrogen usage limitations of a reactor-grade high stiffnesspropylene-based polymer as described previously. The term “visbreaking”(or “cracking”), as used herein, is the thermal and/or chemicaldegradation of a polymer into smaller polymer chain segments.Visbreaking typically includes placing a polymer (such as polypropylene)in a melt state in the presence of a free radical initiator (such as aperoxide) to degrade the polypropylene into smaller polypropylene chainsegments.

Visbreaking has many side effects such as formation of decompositionproducts (which oftentimes cause odor and food incompatibilityproblems), added cost, and a reduction in polymer stiffness. Visbreakingincreases the melt flow yet decreases the weight average molecularweight of a polymer. Visbreaking alters the physical and chemicalstructure of the initial polymer. For example, a visbroken polypropylenehomopolymer will exhibit a reduction in physical and/or mechanicalproperties (i.e. a lower tensile modulus, a lower flexural modulus)compared to an uncracked propylene homopolymer with the same MFR.

In an embodiment, the present process forms an uncracked propylene-basedpolymer. A polymer that is “uncracked” has not been subject to avisbreaking procedure. In other words, an uncracked polymer is anon-thermally and/or non-chemically degraded polymer. An uncrackedpolymer does not exhibit a decline of physical and/or mechanicalproperties related to molecular weight (such as fiexural modulus and/ortensile properties), as does a visbroken polymer at the same MFR. Inaddition, an uncracked polymer does not experience decompositionproducts (which oftentimes cause odor and food incompatibility problems)as does a visbroken polymer.

In an embodiment, the process includes forming propylene-based polymerhaving one or more of the following properties:, (i) an uncrackedpropylene homopolymer; (ii) a MFR greater than 50 g/10 min, or greaterthan 60 g/10 min, or greater than 70 g/10 min, or greater than 100 g/10min ; (iii) a xylene solubles content of less than 4 wt %, or less than3% wt %, or from about 0.1 wt % to less than 2.0 wt %; (iv) a T_(MF)greater than about 165° C., or greater than 170° C.; (v) an ALA contentat least about 5 ppm to about 150 ppm; (vi) a post-reactor oligomercontent (“oligomers” are C₁₂-C₂₁ compounds) less than 3000 ppm, or lessthan 2500 ppm, or from about 500 ppm to about 3000 ppm; and/or (vii) apost-reactor oligomer content about 10%, or about 20%, or about 40% lessthan the corresponding oligomer content of a propylene-based polymerformed by a catalyst composition which contains a singlestiffness-promoting composition SCA (and optionally an ALA) undersimilar polymerization conditions. The term “post-reactor oligomercontent,” as used herein, is the oligomer content of the resultantpropylene-based polymer immediately after exit from the polymerizationreactor. In other words, “post-reactor oligomer content” is the oligomercontent prior to any post-polymerization washing procedure, heatingprocedure, and/or refining procedure.

The present polymerization process may comprise two or more embodimentsdisclosed herein.

In an embodiment, a propylene-based polymer is provided. Thepropylene-based polymer includes at least 5 ppm of an activity limitingagent. The propylene-based polymer has a melt flow rate greater thanabout 50 g/10 min. The ALA may be present in an amount of at least 5ppm,or at least 10 ppm, or at least 20 ppm, or at least about 30 ppm, or atleast about 5 ppm to about 350 ppm. In a further embodiment, the ALA isisopropyl myristate (IPM).

In an embodiment, the propylene-based polymer has a MFR greater than 60g/10 min, or greater than 70 g/10 min, or greater than 80 g/10 min, orgreater than 100 g/10 min, or greater than 50 g/10 min to about 1000g/10 min.

In an embodiment, the propylene-based polymer is uncracked.

In an embodiment, the propylene-based polymer is a propylenehomopotymer.

In an embodiment, the propylene-based polymer includes less than about200 ppm silicon, or from about 1 ppm to about 200 ppm, or from about 2ppm to about 100 ppm silicon. In a further embodiment, thepropylene-based polymer includes from about 1 ppm to about 200 ppmdicylcopentyldimethoxysilane.

In an embodiment, the propylene-based polymer includes a propertyselected from: (i) a xylene solubles content of less than about 4 wt %,or less than about 3% wt %, or from about 0,1 wt % to less than about2.0 wt %; (ii) a T_(MF) greater than about 165° C., or greater thanabout 170° C.; (iii) a post-reactor oligomer content less than, about3000 ppm, or less than about 2500 ppm, or from about 500 ppm to about3000 ppm: and (iv) any combination of (i)-(iii).

In an embodiment, the present propylene-based polymer has low or notoxicity, low or no decomposition products, and/or low or no unpleasantodor.

The present propylene-based polymer may comprise two or more embodimentsdisclosed herein.

DEFINITIONS

All references to the Periodic Table of the Elements herein shall referto the Periodic Table of the Elements, published and copyrighted by CRCPress, Inc., 2003. Also, any references to a Group or Groups shall be tothe Groups or Groups reflected in this Periodic Table of the Elementsusing the IUPAC system for numbering groups. Unless stated to thecontrary, implicit from the context, or customary in the art, all pansand pereents are based on weight, For purposes of United States patentpractice, the contents of any patent, patent application, or publicationreferenced herein are hereby incorporated by reference in their entirety(or the equivalent US version thereof is so incorporated by reference),especially with respect to the disclosure of synthetic techniques,definitions (to the extent not inconsistent with any definitionsprovided herein) and general knowledge in the art.

The term “comprising,” and derivatives thereof, is not intended toexclude the presence of any additional component, step or procedure,whether or not the same is disclosed herein. In order to avoid anydoubt, all compositions claimed herein through use of the term“comprising” may include any additional additive, adjuvant, or compoundwhether polymeric or otherwise, unless stated to the contrary. Incontrast, the term, “consisting essentially of” excludes from the scopeof any succeeding recitation any other component, step or procedure,excepting those that are not essential to operabiiity, The term“consisting of” excludes any component, step or procedure notspecifically delineated or listed. The term “or” , unless statedotherwise, refers to the listed members individually as well as in anycombination.

Any numerical range recited herein, includes all values from the lowervalue to the upper value, in increments of one unit, provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent, or a value of a compositional or a physical property, suchas, for example, amount of a blend component, softening temperature,melt index, etc., is between 1and 100, it is intended that allindividual values, such as. 1, 2, 3, etc., and all subranges, such as, 1to 20, 55 to 70, 197 to 100, etc., are expressly enumerated in thisspecification. For values which are less than one, one unit isconsidered to be 0.0001, 0.001, 0.01 or 0.1, as appropriate. These areonly examples of what is specifically intended, and all possiblecombinations of numerical values between the lowest value and thehighest value enumerated, are to be considered to be expressly stated inthis application. In other words, any numerical range recited hereinincludes any value or subrange within the stated range. Numerical rangeshave been recited, as discussed herein, reference melt index, melt Howrate, and other properties.

The terms “blend” or “polymer blend,” as used herein, is a blend of twoor more polymers. Such a blend may or may not be miscible (not phaseseparated at molecular level). Such a blend may or may not be phaseseparated. Such a blend may or may not contain one or more domainconfigurations, as determined from transmission electron spectroscopy,light scattering, x-ray scattering, and other methods known in the art.

The term “composition,” as used herein, includes a mixture of materialswhich comprise the composition, as well as reaction products anddecomposition products formed from the materials of the composition.

The term “polymer” is a macromolecular compound prepared by polymerizingmonomers of the same or different type. “Polymer” includes homopoiymers,copolymers, terpolymers, interpoiymers, and so on. The term“interpolymer” means a polymer prepared by the polymerization of atleast two types of monomers or comonomers. It includes, but is notlimited to, copolymers (which usually refers to polymers prepared fromtwo different types of monomers or comonomers, terpolymers (whichusually refers to polymers prepared from three different types ofmonomers or comonomers), tetrapolymers (which usually refers to polymersprepared from four different types of monomers or comonomers), and thelike.

The term “interpolymer,” as used herein, refers to polymers prepared bythe polymerization of at least two different types of monomers. Thegeneric term interpolymer thus includes copolymers, usually employed torefer to polymers prepared from two different monomers, and polymersprepared from more than two different types of monomers.

The term “olefin-based polymer” is a polymer containing, in polymerizedform, a majority weight percent of an olefin, for example ethylene orpropylene, based on the total weight of the polymer. Nonlimitingexamples of olefin-based polymers include ethylene-based polymers andpropylene-based polymers.

The term, “ethylene-based polymer,” as used herein, refers to a polymerthat comprises a majority weight percent polymerized ethylene monomer(based on the total weight of polymerizable monomers), and optionallymay comprise at least one polymerized comonomer.

The term, “propylene-based polymer,” as used herein, refers to a polymerthat comprises a majority weight percent polymerized propylene monomer(based on the total amount of polymerizable monomers), and optionallymay comprise at least one polymerized comonomer.

The term “alkyl,” as used herein, refers to a branched or unbranched,saturated or unsaturated acyclic hydrocarbon radical. Nonlimitingexamples of suitable alkyl radicals include, for example, methyl, ethyl,n-propyl, i-propyl, 2-propenyl (or allyl), vinyl, n-butyl, t-butyl,i-butyl (or 2-methylpropyl), etc. The alkyls have 1 and 20 carbon atoms.

The term “substituted alkyl,” as used herein, refers to an alkyl as justdescribed in which one or more hydrogen atom bound to any carbon of thealkyl is replaced by another group such as a halogen, aryl, substitutedaryl, cycloaikyl, substituted cycloalkyl, heteroeyeloalkyl, substitutedheteroeyeloalkyl, halogen, haloalkyl, hydroxy, amino, phosphide, alkoxy,amino, thio, nitro, and combinations thereof. Suitable substitutedalkyls include, for example, benzyl, trifluoromethyl and the like.

The term “aryl,” as used herein, refers to an aromatic substituent whichmay be a single aromatic ring or multiple aromatic rings which are fusedtogether, linked covalently, or linked to a common group such as amethylene or ethylene moiety. The aromatic ring(s) may include phenyl,naphthyl, anthraeenyl, and biphenyl, among others. The aryls have 1 and20 carbon atoms.

Test Methods

Flexural modulus is determined in accordance with ASTM D790-00.

Melt flow rate (MFR) is measured in accordance with ASTM D 1238-01 testmethod at 230° with a 2.16 kg weight for propylene-based polymers.

Xylene Solubles (XS) is measured using a ¹H NMR method as described inU.S. Pat. No, 5,539,309, the entire content of which is incorporatedherein by reference.

Final melting point (T_(MF)) is the temperature to melt the most perfectcrystal in the sample and is regarded as a measure for isotacticity andinherent polymer crystallizabiiity. The test is conducted using a TAQ100 Differential Scanning Calorimeter. A sample is heated from 0° C. to240° C. at a rate of 80° C./min, cooled at the same rate to 0° C., thenheated again at the same rate up to 150° C., held at 150° C. for 5minutes and the heated from 150° C. to 180° C. at 1.25 ° C./min. TheT_(MF) is determined from this last cycle by calculating the onset ofthe baseline at the end of the heating curve.

Testing procedure:

(1) Calibrate instrument with high purity indium as standard.

(2) Purge the instrument head/ceil with a constant 50 ml/min flow rateof nitrogen constantly.

(3) Sample preparation:

Compression mold 1.5 g of powder sample using a 30-G302H-18-CX WabashCompression Molder (30 ton): (a) heat mixture at 230° C. for 2 minutesat contact; (b) compress the sample at the same temperature with 20 tonpressure for 1 minute; (c) cool the sample to 45° F. and hold for 2minutes with 20 ton pressure; (d) cut the plaque into 4 of about thesame size, stack them together, and repeat steps (a)-(c) in order tohomogenize sample.

(4) Weigh a piece of sample (preferably between 5 to 8 mg) from thesample plaque and seal it in a standard aluminum sample pan, Place thesealed pan containing the sample on the sample side of the instrumenthead/cell and place an empty sealed pan In the reference side. If usingthe auto sampler, weigh out several different sample specimens and setup the machine for a sequence.

(5) Measurements:

-   -   (i) Data storage: off    -   (ii) Ramp 80.00° C./min to 240.00° C.    -   (iii) Isothermal for 1.00 min    -   (iv) Ramp 80.00° C./min to 0.00° C.    -   (v) Isothermal for 1.00 min    -   (vi) Ramp 80.00° C./min to 150.00° C.    -   (vii) Isothermal for 5.00 min    -   (viii) Data storage: on    -   (ix) Ramp 1.25° C./min to 180.00° C.    -   (x) End of method

(6) Calculation: T_(MF) is determined by the interception of two lines.Draw one line from the base-line of high temperature. Draw another linefrom through the deflection of the curve close to the end of the curveat high temperature side.

Oligomer content testing method: Oligomer content is measured byextracting a polymer sample overnight in a chloroform solutioncontaining n-hexadecane as an internal standard. An aliquot of theextract is shaken with methanol and then filtered to remove anyprecipitated high molecular weight polypropylene and solid particles.The filtered liquid is injected onto a fused silica capillarychromatography column using cold on-column injection, Relative amountsof the extracted components are calculated based on the weight ofpolymer extracted.

By way of example and not by limitation, examples of the presentdisclosure will now be provided.

EXAMPLES Example 1

(1) Procatalysts:

A. Procatalyst V10B is a commercial SHAC™ 320 catalyst containing 2.52wt % of Ti and 10.34 wt % of di-isobutyl phthalate (DiBP).

B. Procatalyst 1910-29-2 Is prepared according to the procedure forcatalyst 4949-25-1 in U.S. Provisional Patent Application No. 61/141,902filed on Dec. 31, 2008, the entire content of which, is incorporated byreference herein. Procatalyst 1910-29-2contains 3.61 wt % of Ti and14.85 wt % of 3-methyl-5-tert-butyl-1, 2-phenylene dibenzoate.

(2) External Electron Donor Components:

-   592420: (triethoxysilyi)cyclohexane-   BPIQ—Bis(perhydroisoquinolino)dimethoxysilane-   Catepe: 1 -ethoxy-2-n-pentoxybenzene-   D (or D donor): dicyclopentyldimethoxysilane-   DAB-5: 1-ethoxy-2-(6-(2-ethoxyphenoxy)hexyloxy)benzene-   DiBDES: diisobutyldiethoxysilane-   DiPDMS—Diisopropyldimethoxysilane-   DMDMS—Dimethyidimethoxysilane-   DnBDMS: di-n-butyl-dimethoxysiiane-   IPM: isopropyl myristate-   MChDES: methylcyclohexyldiethoxysilane-   MChDMS—Methylcyclohexyldimethoxysilane-   PEEB—Ethyl p-Ethoxybenzoate-   PTES—n-Propyltriethoxysilane-   PTES: n-propyItriethoxysilane-   S-191—POE (15) coco fatty acids ester-   SIB0971.0: benzyltriethoxysilane-   SIB1928.0: benzyltriethoxysilane-   TEOS: tetraethoxysilane

(3) Polymerization:

A. Liquid Phase Polymerization is performed in liquid propylene in a1-gallon autoclave. After conditioning, the reactors are charged with1375 g of propylene and a targeted amount of hydrogen and brought to 62°C. External electron donor component(s) Is added to a 0.27-Mtriethyiaiuminum solution in isooctane and a 5.0 wt % catalyst slurry inmineral oil (as indicated in data tables below) and premixed at ambienttemperature for 20 minutes before being injected into the reactor toinitiate the polymerization. The premixed catalyst components areflushed into the reactor with isooctane using a high pressure catalystinjection pump. After the exotherm, the temperature is controlled to 67°C. Total polymerization time is 1 hour.

Polymer properties, including xylene solubles (XS), oligomer content,and T_(MF) are melt flow dependent. Procataiyst V10B using D donor asSCA is used as a base line. The results are listed in Table 2. Data inTable 2are used to create standard curves (FIGS. 1 and 2) to generateequations for calculating “standard” value for comparison with polymersproduced with catalyst compositions having a M-EED.

TABLE 2 Polymerization Performance and Polymer Properties forDiBP-Procatalyst/D Donor System Total Pro- Oligomers Run Pro- catalystTEAl SCA H₂ Activity MF XS BD (C₁₂-C₂₁) T_(MF) Number catalyst SCA (mg)(mmol) (mmol) (scc) (kg/g-hr) (min/10 g) (%) (g/cc) (ppm) (° C.) *J-0541V10B D 8.4 1.0 0.25 3000 31.9 4.9 2.89 0.43 761 172.3 *J-0542 V10B D 8.41.0 0.25 4500 28.7 7.3 2.49 0.42 1134 172.2 *J-0543 V10B D 8.4 1.0 0.256000 32.6 11.3 2.43 0.43 1038 172.0 *J-0544 V10B D 8.4 1.0 0.25 750031.3 11.9 2.39 0.43 1362 171.9 *J-0546 V10B D 8.4 1.0 0.25 10000 30.819.5 2.38 0.42 1602 171.2 *J-0547 V10B D 8.4 1.0 0.25 15000 37.9 45.72.27 0.42 2372 170.9 *J-0548 V10B D 8.4 1.0 0.25 20000 34.4 60.9 1.770.40 2506 170.8 *J-0549 V10B D 8.4 1.0 0.25 30000 34.8 161.4 1.36 0.393320 170.3 *J-0550 V10B D 8.4 1.0 0.25 40000 23.8 216.7 1.15 0.35 170.3*Comparative

TABLE 3 Polymerization Performance and Polymer Properties forDiBP-Procatalyst/(D + Dialkoxysilane + IPM) System SCA1 + Pro- SCA2 +SCA1/ Run Pro- catalyst TEAl ALA SCA2/ H₂ Number catalyst SCA1/SCA2/ALA(mg) (mmol) (mmol) ALA (scc) *I-0637  V10B D/MChDES/IPM 8.3 2.0 0.2510/0/15 15000 I-0634 V10B D/MChDES/IPM 8.3 2.0 0.25 4/6/15 15000 I-0633V10B D/MChDES/IPM 8.3 2.0 0.25 3.5/6.5/15 15000 I-0660 V10B D/MChDES/IPM8.3 2.0 0.25 2.5/7.5/15 15000 *I-0648  V10B D/DiBDES/IPM 8.3 2.0 0.2510/0/15 15000 I-0641 V10B D/DiBDES/IPM 8.3 2.0 0.25 2.5/7.5/15 15000I-0640 V10B D/DiBDES/IPM 8.3 2.0 0.25 2/8/15 15000 I-0639 V10BD/DiBDES/IPM 16.7 2.0 0.25 1.5/8.5/15 15000 I-0638 V10B D/DiBDES/IPM 8.32.0 0.25 1/9/15 15000 *O-0610   V10B D/DnBDMS/IPM 8.3 2.0 0.25 10/0/1515000 O-0612  V10B D/DnBDMS/IPM 8.3 2.0 0.25 6.5/3.5/15 15000 O-0611 V10B D/DnBDMS/IPM 8.3 2.0 0.25 5/5/15 15000 O-0614  V10B D/DnBDMS/IPM8.3 2.0 0.25 7/10.5/7.5 15000 Total Total MF Oligomers Oligomers RunActivity (min/ XS BD (C₁₂-C₂₁) (C₁₂-C₂₁) T_(MF) T_(MF)(D) Number(kg/g-hr) 10 g) (%) (g/cc) (ppm) (D) (ppm) (° C.) (° C.) *I-0637  40.737.1 1.66 0.41 171.4 171.2 I-0634 35.7 55.0 2.34 0.41 171.0 171.0 I-063339.2 60.5 2.52 0.40 1603 2455 170.5 170.9 I-0660 39.0 85.8 2.18 0.401442 2699 170.5 170.7 *I-0648  36.5 39.0 1.88 0.39 2095 2150 171.4 171.1I-0641 23.0 64.1 2.38 0.35 170.5 171.0 I-0640 21.0 62.7 2.52 0.35 170.8170.9 I-0639 19.7 80.3 2.40 0.40 170.7 170.9 I-0638 19.5 79.0 2.96 0.35170.5 170.7 *O-0610   10.1 39.1 1.74 0.35 1672 2152 171.8 171.1 O-0612 32.0 57.2 2.24 0.39 1843 2417 170.9 170.9 O-0611  21.3 71.0 2.28 0.371938 2567 170.4 170.8 O-0614  24.1 90.7 2.60 0.38 1773 2738 170.8 170.7*= Comparative

TABLE 4 Polymerization Performance and Polymer Properties forDiBP-Procatalyst/(D + Trialkoxysilane + IPM) System SCA1 + Pro- SCA2 +SCA1/ Run Pro- catalyst TEAl ALA SCA2/ H₂ Number catalyst SCA1/SCA2/ALA(mg) (mmol) (mmol) ALA (scc) J-0612 V10B D/PTES/IPM 8.3 2.0 0.25 5/5/1515000 J-0611 V10B D/PTES/IPM 8.3 2.0 0.25 4.5/5.5/15 15000 J-0609 V10BD/PTES/IPM 8.3 2.0 0.25 3.5/6.5/15 15000 J-0608 V10B D/PTES/IPM 8.3 2.00.25 3/7/15 15000 J-0634 V10B D/PTES/IPM 8.3 2.0 0.25 2.5/7.5/15 15000J-0606 V10B D/PTES/IPM 8.3 2.0 0.25 2/8/15 15000 *L-0907  V10BD/SIB0971.0/IPM 7.2 2.0 0.25 10/0/15 15000 *L-0911  V10B D/SIB0971.0/IPM7.2 2.0 0.25 0/10/15 15000 L-0904  V10B D/SIB0971.0/IPM 7.2 2.0 0.253/7/15 15000 L-0906  V10B D/SIB1928.0/IPM 7.2 2.0 0.25 3/7/15 15000*L-0908  V10B D/592420/IPM 7.2 2.0 0.25 0/10/15 15000 L-0909  V10BD/592420/IPM 7.2 2.0 0.25 3/7/15 15000 *K-0907  V10B D/SIB0971.0/IPM 7.22.0 0.25 10/0/15 20000 *K-0911  V10B D/SIB0971.0/IPM 7.2 2.0 0.250/10/15 20000 K-0904  V10B D/SIB0971.0/IPM 7.2 2.0 0.25 3/7/15 20000*K-0905  V10B D/SIB1928.0/IPM 7.2 2.0 0.25 0/10/15 20000 K-0906  V10BD/SIB1928.0/IPM 7.2 2.0 0.25 3/7/15 20000 *K-0908  V10B D/592420/IPM 7.22.0 0.25 0/10/15 20000 K-0909  V10B D/592420/IPM 7.2 2.0 0.25 3/7/1520000 Total Total MF Oligomers Oligomers Run Activity (min/ XS BD(C₁₂-C₂₁) (C₁₂-C₂₁) T_(MF) T_(MF)(D) Number (kg/g-hr) 10 g) (%) (g/cc)(ppm) (D) (ppm) (° C.) (° C.) J-0612 29.4 63.0 1.74 0.40 1436 2484 170.9170.9 J-0611 31.7 63.9 3.13 0.41 1973 2493 171.0 170.9 J-0609 35.7 86.72.26 0.39 2289 2706 170.4 170.7 J-0608 31.9 102.6 2.43 0.39 2345 2824170.5 170.6 J-0634 24.7 113.8 2.70 0.34 2182 2895 170.3 170.5 J-060630.7 122.3 2.33 0.39 2332 2946 170.4 170.5 *L-0907  28.9 32.9 1.88 0.39*L-0911  21.7 350.5 2.57 0.34 L-0904  35.8 77.7 (NM) 0.37 L-0906  29.276.5 2.11 0.37 *L-0908  8.8 186.1 3.26 0.32 L-0909  30.7 39.8 2.12 0.34*K-0907  32.5 61.3 1.88 0.40 *K-0911  25.6 663.5 2.72 0.34 K-0904  43.5150.3 1.91 0.39 *K-0905  9.2 582.8 3.32 0.32 K-0906  31.3 144.1 2.240.38 *K-0908  11.0 344.5 2.93 0.32 K-0909  27.8 96.6 1.93 0.38 *=Comparative

TABLE 5 Polymerization Performance and Polymer Properties forDiBP-Procatalyst/(D + Tetraalkoxysilane + IPM) System SCA1 + Pro- SCA2 +SCA1/ Run Pro- catalyst TEAl ALA SCA2/ H₂ Number catalyst SCA1/SCA2/ALA(mg) (mmol) (mmol) ALA (scc) P-0622 V10B D/TEOS/IPM 8.3 2.0 0.25 5/5/1515000 P-0620 V10B D/TEOS/IPM 8.3 2.0 0.25 4.5/5.5/15 15000 P-0619 V10BD/TEOS/IPM 8.3 2.0 0.25 4/6/15 15000 P-0617 V10B D/TEOS/IPM 8.3 2.0 0.253/7/15 15000 P-0616 V10B D/TEOS/IPM 16.7 2.0 0.25 2.5/7.5/15 15000P-0615 V10B D/TEOS/IPM 8.3 2.0 0.25 2/8/15 15000 Total Total MFOligomers Oligomers Run Activity (min/ XS BD (C₁₂-C₂₁) (C₁₂-C₂₁) T_(MF)T_(MF)(D) Number (kg/g-hr) 10 g) (%) (g/cc) (ppm) (D) (ppm) (° C.) (°C.) P-0622 37.3 71.7 2.17 0.38 1851 2574 170.8 170.8 P-0620 38.3 75.22.15 0.38 2067 2607 170.5 170.8 P-0619 38.8 82.2 2.16 0.40 1940 2669170.6 170.7 P-0617 28.8 109.8 1.93 0.38 1863 2871 169.6 170.6 P-061636.3 120.1 2.78 0.37 2083 2933 170.1 170.5 P-0615 16.1 165.2 2.71 0.341984 3155 170.0 170.3

TABLE 6 Polymerization Performance and Polymer Properties forDiBP-Procatalyst/(D + Non-Silane SCA + IPM) System SCA1 + Pro- SCA2 +SCA1/ Run Pro- catalyst TEAl ALA SCA2/ H₂ Number catalyst SCA1/SCA2/ALA(mg) (mmol) (mmol) ALA (scc) *O-0616   V10B D/DAB-5/IPM 8.3 2.0 0.2525/0/0 15000 *O-0625   V10B D/DAB-5/IPM 8.3 2.0 0.25 10/0/15 15000O-0622  V10B D/DAB-5/IPM 8.3 2.0 0.25 2/8/15 15000 *P-0603  V10BD/catepe/IPM 8.3 2.0 0.25 25/0/0 15000 *P-0614  V10B D/catepe/IPM 8.32.0 0.25 10/0/15 15000 P-0613 V10B D/catepe/IPM 8.3 2.0 0.25 5/5/1515000 P-0611 V10B D/catepe/IPM 8.3 2.0 0.25 3/7/15 15000 P-0610 V10BD/catepe/IPM 8.3 2.0 0.25 2/8/15 15000 P-0609 V10B D/catepe/IPM 8.3 2.00.25 1/9/15 15000 Total Total MF Oligomers Oligomers Run Activity (min/XS BD (C₁₂-C₂₁) (C₁₂-C₂₁) T_(MF) T_(MF)(D) Number (kg/g-hr) 10 g) (%)(g/cc) (ppm) (D) (ppm) (° C.) (° C.) *O-0616   19.4 30.3 1.70 0.39 21311973 171.7 171.3 *O-0625   18.4 37.0 1.64 0.37 1832 2112 171.3 171.2O-0622  7.1 50.0 2.69 0.34 1892 2322 170.7 171.0 *P-0603  15.9 38.5 1.480.37 1868 2141 171.4 171.2 *P-0614  38.3 38.6 1.70 0.41 2028 2143 171.3171.2 P-0613 32.9 81.9 2.68 0.40 2260 2666 170.0 170.7 P-0611 31.7 161.63.28 0.37 2656 3140 169.1 170.3 P-0610 28.8 201.0 3.91 0.36 2964 3292168.5 170.2 P-0609 11.1 197.5 3.39 0.33 1868 3280 168.3 170.2 *=Comparative

TABLE 7 Polymerization Performance and Polymer Properties forNon-DiBP-Procatalyst/(D + Tetraalkoxysilane + IPM) System SCA1 + Pro-SCA2 + SCA1/ Run Pro- catalyst TEAl ALA SCA2/ H₂ Number catalystSCA1/SCA2/ALA (mg) (mmol) (mmol) ALA (scc) *O-0953 1910-29-2 D/TEOS/IPM4.8 2.0 0.25 25/0/0 15000  O-0972 1910-29-2 D/TEOS/IPM 5.9 2.0 0.252.5/7.5/15 15000 Total Total MF Oligomers Oligomers Run Activity (min/XS BD (C₁₂-C₂₁) (C₁₂-C₂₁) T_(MF) T_(MF)(D) Number (kg/g-hr) 10 g) (%)(g/cc) (ppm) (D) (ppm) (° C.) (° C.) *O-0953 29.0 41.3 1.43 0.25  O-097230.9 101.2 2.24 0.26 *= Comparative

Example 2

(1) Procatalyst: A commercial SFIAC™ 320 catalyst (2.59% Ti) and DiBP isused. Catalyst slurries are prepared in toluene at 0.247 mg/rni. AllSCAS and ALAs are diluted to 0.005 M in Isopar E™, except S-191 which isdissolved in toluene before injection into the PPRs. TEA1 is prepared inIsopar E™ and used as either 0.02 or 0.1 M solutions.

(2) Polymerization: Purged Parallel Polymerization Reactors (PPR) areheated to 50° C., TEA1 and Isopar E™ make-up solvent were added to eachreactor, followed by the addition of H₂ to a stabilized pressure of 5psig. Reactors are heated to the assigned temperature (67, 100 or 115°C.). Propylene is added to 100 psig and allowed to stabilize for 10 min.To each reactor is added SCA or mixture of SCA1, SCA2 & ALA 500 ulIsopar E™ chaser and immediately followed by the addition of catalyst(275 ul) and a 500 ul Isopar E™ chaser. Reactions are quenched with CO₂after 60 minutes or when the maximum relative conversion of 110 wasreached.

(3) Calculation: The concentration of propylene in Isopar E™ in PPRs atvarious temperatures is calculated. Table 8 below provides normalizedactivity ratios and illustrates the self-limiting property of thepresent catalyst compositions. For DMDMS/MChDMS 50/50, the ratio of thenormalized catalyst activity at 100° C. to the activity at 67° C.,A/A67, is 43% (Table 8). By keeping the DMDMS/MChDMS ratio at 1/1 whilereplacing 95% of the donor mixture with PEEB, the DMDMS/MChDMS/PEEB2.5/2.5/95 system showed a ratio A/A67 at 100° C. of 21%. This meansthat the catalyst system has a significantly lower activity compared tothe activity at 67° C. after PEEB was added. That is, the catalyst ismore “self-limiting”. The same trend is also true for the 115° C.activity.

The self-limiting property of the present catalyst composition is alsoobserved for other SCA1/SCA2/ALA systems composed of aikylalkoxysilanessuch as DiPDMS/TEOS, DCPDMS/TEOS, and DCPDMS/MChDMS in the presence ofand ALA, such as PEEB. When PEEB is replaced with a poly(alkyleneglycol) ester compound, such as S-191, the self-limiting effect isprofound (Table 8) even at higher Al/M-EED molar ratio. Similar resultsare observed when the ALA is isopropyl myristate (1 PM).

TABLE 8 A1/(SCA1 + (SCA1 + Normal- SCA2 + SCA1/SCA2/ SCA2)/ Average izedALA) ALA/Ti ALA Temp Activity Activity Activity A/A67 SCA1 SCA2 ALA(mol/mol) (mol/mol/mol) (mol %) (° C.) (kg/g/hr (kg/g/hr) (kg/g/hr) (%)DMDMS MChDMS 3.0 15/15/01 100/0   67 4.51 5.19 4.85 4.85 100 100 1.340.93 0.96 1.08 2.08 43 115 0.31 0.21 0.28 0.27 0.64 13 DMDMS MChDMS PEEB3.0 0.75/0.75/28.5/1 5/95 67 3.72 3.62 4.50 3.95 3.95 100 100 0.24 0.340.36 0.78 0.43 0.83 21 115 0.03 0.01 0.01 0.04 0.02 0.05 1 DiPDMS TEOS3.0 3/27/0/1 100/0   67 4.22 4.01 4.12 4.12 100 100 0.71 0.89 1.03 0.881.69 41 115 0.24 0.14 0.22 0.20 0.48 12 DiPDMS TEOS PEEB 3.00.3/2.7/27/1 10/90  67 2.99 3.11 3.88 3.33 3.33 100 100 0.22 0.26 0.310.41 0.30 0.58 17 115 0.05 0.04 0.05 0.03 0.04 0.10 3 DiPDMS TEOS S-19116.7 0.3/2.7/27/1 10/90  67 4.00 4.26 3.36 3.87 3.87 100 100 0.06 0.060.06 0.06 0.12 3 115 0.06 0.07 0.06 0.06 0.15 4 DCPDMS TEOS 3.0 9/21/0/1100/0   67 3.98 4.71 4.35 4.35 100 100 1.14 1.03 0.90 1.02 1.98 45 1150.33 0.23 0.30 0.29 0.69 16 DCPDMS TEOS PEEB 3.0 0.3/2.7/27/1 10/90  673.85 3.85 4.12 3.96 3.96 100 100 0.47 0.47 0.44 0.41 0.45 0.86 22 1150.08 0.08 0.07 0.08 0.08 0.19 5 DCPDMS TEOS S-191 16.7 0.3/2.7/27/110/90  67 4.70 5.03 3.30 4.34 4.34 100 100 0.06 0.06 0.07 0.06 0.12 3115 0.06 0.06 0.06 0.06 0.14 3 DCPDMS MChDMS 3.0 15/15/011 100/0   6720.44 4.94 5.60 10.33 10.33 100 100 2.33 2.26 2.51 2.37 4.57 44 115 0.840.70 0.78 0.77 1.85 18 DCPDMS MChDMS PEEB 3.0 0.75/0.75/28.5/1 5/95 674.73 5.60 10.21 8.11 7.16 7.16 100 100 0.60 0.21 0.75 0.90 0.62 1.19 17115 0.08 0.10 0.07 0.07 0.08 0.19 3 DCPDMS MChDMS S-191 16.70.75/0.75/28.5/1 5/95 67 5.34 5.66 11.72 7.57 7.57 100 100 0.06 0.060.06 0.06 0.12 2 115 0.07 0.06 0.06 0.06 0.15 2 BPIQ PTES 3.0 15/15/0/1100/0   67 3.33 4.17 3.75 3.75 100 100 1.29 1.64 1.41 1.45 2.79 74 1150.46 0.54 0.38 0.46 1.10 29 BPIQ PTES PEEB 3.0 0.75/0.75/28.5/1 5/95 674.70 2.80 4.78 4.09 4.09 100 100 0.43 0.62 0.23 0.43 0.82 20 115 0.060.05 0.05 0.04 0.05 0.12 3 BPIQ PTES S-191 16.7 0.75/0.75/28.5/1 5/95 673.56 2.94 2.72 3.07 3.07 100 100 0.06 0.06 0.06 0.06 0.12 4 115 0.060.06 0.06 0.06 0.14 5

Catalyst compositions containing an M-EED as disclosed herein areself-limiting systems while simultaneously retaining the advantages ofmultiple SCAs. Provision of a melt flow-promoting composition such asSCA2 increases the MFR of the resultant polymer. Catalyst compositionswith a M-EED produce a polymers with a stiffness substantially the sameas, or the same as, the polymer stiffness resulting from a catalystcomposition having a stiffness-promoting composition (such asdicylcopentyidimethoxysilane) as the only external electron donor.Provision of a stiffness-promoting composition such as SCA1 produces apolymer with high stiffness as exemplified by the T_(MF)values in Tables2-7.

Total oligomer content for polymers produced with the present catalystcomposition is significantly reduced compared to the oligomer contentwhen a stiffness-promoting composition (such asdicyelopentyldimethoxysilane) is used as the sole external donor at thesame melt flow.

The present polymers are not visbroken and have high melt flow, highstiffness as well as low oligomer content, low or no toxicity, and/orlow or no decomposition products.

It is specifically intended that the present Invention not be limited tothe embodiments and illustrations contained herein, but include modifiedforms of those embodiments including portions of the embodiments andcombinations of elements of different embodiments as come within thescope of the following claims.

I claim:
 1. A polymerization process comprising: contacting propyleneand optionally at least one other olefin with a catalyst composition ina polymerization reactor under polymerization conditions, the catalystcomposition comprising (i) a procatalyst comprising a phenylenedibenzoate comprising:

wherein R₁-R₁₄ are the same or different; each of R₁-R₁₄ is selectedfrom hydrogen, a substituted hydrocarbyl group having 1 to 20 carbonatoms, an unsubstituted hydrocarbyl group having 1 to 20 carbon atoms, ahalogen, or combinations thereof; and at least one of R₁-R₁₄ is nothydrogen; (ii) a cocatalyst and (iii) a mixed external electron donor(M-EED) comprising a first selectivity control agent (SCA1), a secondselectivity control agent (SCA2) different from SCA1, and an activitylimiting agent (ALA), wherein the SCA1:SCA2 mole ratio is less than orequal to 1.0, the total SCA:ALA mole ratio is 0.43-2.33:1, and the SCA1to total SCA mole ratio is 0.2-0.5:1; controlling the mole ratio of (1)SCA1 to SCA2, and/or (2) total-SCA to ALA, and/or (3) SCA1 to total SCA;and forming a propylene-based polymer having a melt flow rate of atleast 50 g/10 min as measured in accordance with ASTM D 1238-01 at 230°C. with a 2.16 kg weight.
 2. The process of claim 1 comprisingself-limiting the polymerization when the temperature in thepolymerization reactor is greater than about 100° C.
 3. The process ofclaim 1 comprising forming a propylene-based polymer comprising at leastabout 5 ppm ALA.
 4. The process of claim 1 comprising forming anuncracked propylene-based polymer.
 5. The process of claim 1 wherein theSCA1 is a dimethoxysilane.
 6. The process of claim 1 wherein the SCA1 isdicyclopentyldimethoxysilane.
 7. The process of claim 1 wherein the SCA2is a triethoxysilane.
 8. The process of claim 1 wherein the ALA is aC₄-C₃₀ aliphatic acid ester.
 9. The process of claim 1 wherein the ALAis isopropyl myristate.
 10. The process of claim 1 wherein the phenylenedibenzoate is 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate.
 11. Theprocess of claim 1 comprising forming a propylene-based polymer having amelt flow rate of greater than 60 g/10 min as measured in accordancewith ASTM D 1238-01 at 230° C. with a 2.16 kg weight.
 12. The process ofclaim 1 comprising forming a propylene-based polymer having a melt flowrate of greater than 70 g/10 min as measured in accordance with ASTM D1238-01 at 230° C. with a 2.16 kg weight.
 13. The process of claim 1comprising forming a propylene-based polymer having a melt flow rate ofgreater than 100 g/10 min as measured in accordance with ASTM D 1238-01at 230° C. with a 2.16 kg weight.
 14. The process of claim 1 comprisingforming a propylene-based polymer having a xylene solubles content ofless than 3%.
 15. The process of claim 1 wherein the phenylenedibenzoate is 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate, the SCA1is dicyclopentyldimethoxysilane, the SCA2 is a triethoxysilane and theALA is isopropylmyristate.
 16. The process of claim 1, forming thepropylene-based polymer to include at least 5 ppm ALA.
 17. The processof claim 1, wherein the catalyst composition includes Al, and theprocess further comprises controlling a mole ratio of Al to total SCA1,SCA2 and ALA in the range of 0.5-25:1.
 18. The process of claim 1,wherein SCA1 comprises a dimethoxysilane compound and SCA2 comprises adiethoxysilane compound.
 19. A polymerization process comprising:contacting propylene and optionally at least one other olefin with acatalyst composition in a polymerization reactor under polymerizationconditions, the catalyst composition comprising (i) a procatalystcomprising a phenylene dibenzoate comprising:

wherein at least one of R₁-R₄ is selected from an unsubstitutedhydrocarbyl group having 2 to 20 carbon atoms and or a substitutedhydrocarbyl group having 2 to 20 carbon atoms; each of the other Rgroups of R₁-R₄is hydrogen; and each of R₅-R₁₄ is selected fromhydrogen, an unsubstituted hydrocarbyl group having 1 to 20 carbonatoms, a substituted hydrocarbyl group having 1 to 20 atoms, a halogen,and or combinations thereof; (ii) a cocatalyst and (iii) a mixedexternal electron donor (M-EED) comprising a first selectivity controlagent (SCA1), a second selectivity control agent (SCA2) different fromSCA1, and an activity limiting agent (ALA), wherein the SCA1:SCA2 moleratio is less than or equal to 1.0, the total SCA:ALA mole ratio is0.43-2.33:1, and the SCA1 to total SCA mole ratio is 0.2-0.5:1;controlling the mole ratio of (1) SCA1 to SCA2, and/or (2) total-SCA toALA, and/or (3) SCA1 to total SCA; and forming a propylene-based polymerhaving a melt flow rate of at least 50 g/10 min as measured inaccordance with ASTM D 1238-01 at 230° C. with a 2.16 kg weight.
 20. Theprocess of claim 19, forming the propylene-based polymer to include atleast 5 ppm ALA.
 21. The process of claim 19, wherein the catalystcomposition includes Al, and the process further comprises controlling amole ratio of Al to total SCA1, SCA2 and ALA in the range of 0.5-25:1.22. The process of claim 19, wherein SCA1 comprises a dimethoxysilanecompound and SCA2 comprises a diethoxysilane compound.